Ultra high frequency oscillator and amplifier



Feb. 11, 1947.. c. E. HALLER.

ULTRIPHIGH FREQUENCY OSCILLATOR AND AMPLIFIER Filed Oct. 17, 1942 3Sheets-Sheet 1 Fz'gal.

INVENTO Feb. 11, 1947. c. E. HALL'ER ULTRA-HIGH FREQUENCY OSCILLATOR ANDAMPLIFIER Filed Oct. 17, 1942 3 Sheets-Sheet 2 M. 1 5 W MW 4 v a 4 M 4 ua 8 5 v 4 M W4 /0- INVENTOR v WW ATTORNEY Feb. 11, 1947. c. E. HALLER ,4

ULTRA -HIGH FREQUENCY OSCILLATQR AND AMPLIFIER Filed on. 17, 1942 sSheets-Sheet s INVENTOR CeelZEmr 4mm;

ATTORNEY Patented Feb. 11, 1947 UNITED STATES PTENT OFFICE nicerrnnoocncr oscittsron AND AMPLKFIER Cecil E. Heller, Bloomfield, N. 3.,assigncr to Radio @orporation of America, a corporation of Delaware 21Claims.

. High Q Sufficient mechanical dimensions Low radiation Low surgeimpedance lines in order to (a) Prevent excessive line shortening, if

possible, due to tube capacity.

(b) Aid getting a balanced circuit (c) Minimize the eiiect of straycapacities so that they do not become a troublesome item.

power and grid return at points in the circult Where no F, voltageexists.

in conventional tubes employed in conventional circuits, it is to obtainthese desirable characteristics.

. Convenient means of introducing the D. C.

diflicult if not sometimes impossible I It is, thcreiore, an object ofmy invention to provide an electron discharge device and associate-clcircuit particularly suitable for use at ultra high frequencies.

Another object of my invention is to provide a circuit particularlysuitable for use with electron discharge devices designed for ultra highfrequency use and provided with a plurality of leads for each ofelectrodes.

Another object of my invention is to provide a stable high frequencyoscillator for use at frequencies up to 1200 inegacycles and more.

A further object of my invention is to provide such an oscillator inwhich undesired radiation is reduced to a minimum.

A still further object of my invention is to provide a combinedoscillator and power amplifier utilizing electron discharge device ofthe type described which compact and fully shielded.

Another object of my circuit for use at ultra high frequencies but ofample mechanical dimensions,- having high Q, and provided withconvenient means for introducing electrode voltages at points in thecircuit where no R.-F. voltages exist.

The novel features which I believe to be characteristic of my inventionare set forth with particularity the appended claims, but the inventionitself will best be understood b reference to the following descriptiontaken in connection with the accompanying drawings in which Figure l isa top View with cover removed of an electron discharge device andassociated circuit made 2. cording to my invention and used as an ultrahigh invention is to provide a eniency oscillator, Figure 2 is alongitudinal 3' along the line 2-2 of Figure 1, lELlTBS-J 3 and a areschematic diagrams illusiie according to invention, and Figure 7 isschematic circuit diagram of the apparatus 51 own in Figure 6 and itsassociated voltage sources.

In accordance with my invention I utilize an electron discharge deviceparticularly designed for ul ra high frequencies and provided with pairsof oppositely extending electrode leads and supports which reduce tubeinductance and capacity when used at ultra high frequencies. These leadspsi t utilization of novel circuit apparatus made according to myinvention.

l et'erring to Figures 1 and 2, the electron dis ce device utilized inaccordance with my inon comprises an envelope it and contains a cathodell, grid l2 and anode the grid l2 and 1 mole being provided withoppositely extendleads and supports l t--54 and ll5. The device isprovided with cathode heater leads it and cathode lead ll connected anddisposed in a manner to be described.

The oscillator circuit comprises concentric consive collars orring-1ilre members l8l llCh supporta pair of electron discharge devicesbetwcen them as illustrated, the collars being provided with clip-likeengaging elements M and ill for engaging the leads M and i5. Surroundingthe electron. discharge device and the oscillator circuit proper andacting as a shielding member is a drum-lilre member Eli provided with aclosed bottom 23 and removable top 2d, The ring members are supportedfrom the member i b means of the insulatin supports 2! and Extendingfrom the bottom of the shielding member is a tubular extension 25through which the cathode leads 2t and 2'5 extend, a conducting membercontacting these tubular members for tuning the same in a manner and fora purpose to be described. As illustrated the cathode heater extendthrough and are shielded by the elements 25 and 2?, the cathode leadproper ll being electrically connected to the outside of these tub ormembers.

To tune the circut I provide a plurality of rotatable condenser elementsso, 35, 82 and 33, which extend between. but are out of conta ct withthe collar elements it and i9. Oppositely disposed elements ti and 33are supported on an arm 35 while elements 3!) and 32 are su ported on anarm 38. These arms are in turn supported by coaxial concentric shafts 3iand 38 connected to an electrical gear box 39 provided with a cornventional arrangement of gears whereby the turning of a knob 40connected to the gear mechanism will cause condenser elements 38, 31,and 32, 33 to move away or toward each other as desired.

The member 20 is provided with aperture 45 through which the couplingloop 46 extends for taking energy from within the shielding member 20 toa load or a radiator.

The schematic circuit diagram shown in Figure 5 shows the electricalrelationship between the various elements and the voltage sources. Theanode collar I 9 is connected through a choke 41 to a source of positivepotential whereas the grid collar I8 is connected through a biasingresistor 48 to ground. The shielding structure comprising the elements20, 23, 24, 25 and 2B are also grounded. The cathode heater voltage issupplied by means of transformer 49.

The collar members I8 and [9, which are closed loops, serve asinductances for the oscillator, Whereas the natural capacity betweenthese elements plus the capacity of the tuning condensers provide thecapacity for a resonant circuit driven by the electron discharge devicesIf]. Proper positioning of the shorting disc 23 will adjust theimpedance of the cathode lines so that they offer feedback impedance toR.-F. currents attempting to travel along the conductors 26 and 27, suchthat proper grid excitation is obtained.

In Figure 3 is illustrated somewhat schematically the collar-likeelements l8 and I9 which have been developed into parallel strips withthe grids and anodes connected to opposite strips. As there indicatedthe distance between the anode and grid connections, and between theends of the line and between the anode elements is equal to a'half and aquarter wavelength. In other words, the electron discharge devices arespaced a half wavelength from each other. With this arrangement thevoltage loop appears at the point of anode connection and the nodemidway between the same. Thus the effect is that of closed loops each ahalf wavelength long, the equivalent circuit of two such loops beingshown in Figure 4. The capacity 43 is that capacity represented by theelectrode elements and the loops 4| and 42 represent the inductance ofthat part of the collars l8 and I9 between the electrode elements andthe nodal point on the collars. It will be observed that the result is aresonant circuit which will oscillate if properly driven, that is if analternating voltage is applied across the plates of the condenser 43which is the function of the electron discharge devices. Energy from theplate circuit to the grid circuit to support oscillation is chieflythrough the capacity coupling between the collar elements, the electrondischarge devices acting in push-pull.

While normally the device is operated with the cover 24 in place, thecover may be removed and the screening member 20, 23 used as a reflectorfor focusing the radio beam in any desired direction.

In connection with the tuning elements 30, 3|, 32 and 33, as theseelements are moved closer to the electron discharge devices It! theresonant frequency of oscillation of the oscillator is reduced and asthe elements are moved farther away from the electron discharge devicesthe resonant frequency of oscillation is increased. Moving the elementaway from the device I0 is the equivalent of tapping a condenser acrossfewer and fewer turns of an inductor in an oscillator tank circuit,whereas in moving the elements toward the electron discharge device isequivalent to including more and more turns of the inductor between theterminals of a condenser bridged across the inductor so that at thetube, it is the equivalent of placing the condenser across all of theturns of the inductor, thereby decreasing the resonant frequency of thecircuit.

With an apparatus made according to my invention and utilizing tubes ofthe type described, and using a 5 inch diameter outer copper cylinderand a l inch diameter inner copper cylinder, both 2 inche wide and 20mils thick, I have obtained a frequency of operation of about 830megacycles. Under certain conditions of operation the apparatus has alsobeen made to operate at 1224 megacycles. Oscillations will start atabout 300 volts on the plate with a power output from 8 to 10 watts.

In the modification shown in Figures 6 and '7 my invention is applied toa combined oscillator and grounded grid power amplifier. In thisarrangement the oscillator comprises the lower section in which tubes IDare mounted between the concentric collar cylinders l8 and 19', The gridleads are connected to member I 8' and the anode leads to member IS. Thetubes and the cylinders are mounted within a shielding arrangementcomprising cylinder 50 closed at the top and bottom by covers 52 and 5|.oppositely extending tubular members 53 and 54 surround the coaxialcathode lines 55 and 56 shorted by the elements 51 and 58 and closed bymeans of the insulating discs 59 and B0. The member 50 is divided intotwo compartments by means of transverse partition 6|.

The upper compartment encloses the amplifier. It includes the tubes IDmounted between the cylinders 62 and 63. The member 63 is electricallyconnected to the shielding casing 50. The cylinder 62 is connected tothe anode leads and the cylinder 63 to the grid leads. Thus the grid inthe amplifier is grounded on the shielding apparatus. The uppercompartment is provided with the cathode lead tuning extensions 64 and65 coaxial with and surrounding cathode leads 66 and 61, the tuningbeing accomplished by the shorting discs 68 and 69. The members 64 and23 are closed by the insulating closure members To couple the oscillatorto the amplifier I provide a pair of coupling members 14 and I5 shieldedagainst radiation by means of tubular elements 1-6 and 11, thus formingcoaxial lines. The cathode lines are so turned as to present a variablecapacitive reactance which may be adjusted so that proper excitation isobtained. The R.-F. field within the members 53 and 5d furnishes thenecessary energy for the coupling loops M and 15 which in turn excitethe space within the tubular members 64 and 65 for feeding energy to thecathode of the tubes in the amplifier. The circuit relationships andvoltage sources are best shown in Fig. '7.

As shown a high positive voltage is supplied to the inner cylinder l9through choke 8| in the oscillator and to the inner cylinders 62 throughchoke in the amplifier. The cathodes are heated by means of the heatingtransformer 18, i9, 83 and 84. Energy may be taken from the amplifier bymeans of the coupling loop 13 extending through aperture 12 in the outercylinder 50.

In operation the oscillator portion of the apparatus is made to functionin the same manner as the apparatus shown in Figure 1. Energy from thecathode circuits 55, 53 and 54, 56 which are tuned for proper gridexcitation of the oscillator, is transferred by means of the coaxiallines and loops id--l and l5'l'i, which feed energy into the cathodecircuit of the amplifier tube and the amplifier portion of theapparatus. Thus an R.F. voltage is applied between the cathode and gridof the amplifiers within the upper portion of the member 58, controllingthe flow of current to the anodes of the electron discharge devices andexciting the space between the collar member 92 and collar member 53,energy being taken from this space by means of coupling loop l3extending through aperture 72 in member 50.

While I have indicated the preferred embodiment or my invention of whichI am now aware and have also indicated only one specific application iorwhich my invention may be employed, it will be apparent that myinvention is by no means limited to the exact forms illustrated or theuse indicated, but that many variations may be made in the particularstructure used and the purpose for which it is employed withoutdeparting from the scope of my invention as set forth in the appendedclaims.

What I claim as new is:

1. An oscillator including a plurality of electron discharge devices,each of which has grid and an anode, and a pair of concentriccollar-like elements, one of said elements being connected to the gridsof said electron discharge devices and the other of said collar-likeelements being connected to the anodes of said electron dischargedevices, said electron discharge devices being spaced around saidcollar-like elements.

2. An oscillator including a plurality of electron discharge devices,each of which has a grid and an anode, each grid and each anode beingpro vided with a plurality of leads, and a pair of concentriccollar-like elements, said electron discharge devices being oppositelydisposed and spaced around said collar-like elements, all of the gridleads being connected to one of said collar-like elements and all of theanode leads being connected to the other of said collar-like elements.

3. An oscillator including a plurality of electron discharge devices,each of which has a cathode and an anode, each cathode and each anodebeing provided with a plurality of leads, and a pair of concentriccollar-like elements, said electron discharge devices being oppositelydisposed, all of the grid leads being connected to one of saidcollar-like elements and all of the anode leads being connected to theother of said collar-like elements, and means capacitively coupledbetween said collar-like elements and movable between said electrondischarge devices.

An oscillator circuit for an electron discharge device having anelongated envelope and having grid and anode electrodes, said grid andanode electrodes each being provided with a plurality of terminal leads,said circuit including a pair of concentric collar-like elements ofconducting material, said concentric collar-like elements being providedwith registering apertures through which said electron discharge deviceextends between said collar-like elements with the elongated dimensionof the envelope perpendicular to the axis of said collar-like elements,one of said collar-like elements being connected to said grid leads ndthe other collar-like element being connected to said anode leads forexciting said oscillator circuit.

5. An oscillator circuit for an electron discharge device having anelongated envelope and having grid and anode electrodes, said grid andanode electrodes each being provided with a plurality of terminal leads,said circuit including a pair of concentric collar-like elements ofconducting material, said concentric collar-lik elements being providedwith registering apertures through which said electron discharge deviceextends between said collar-like elements with the elongated dimensionof said envelope perpendicular to the axis of said collar-like elements,one of said collar-like members being connected to the grid leads andthe other collar-like element being connected to the anode leads forexciting said oscillator circuit, and hollow conducting meanssurrounding the concentric collar-like elements of conducting material.

6. An oscillator circuit for an electron discharge device having acathode, grid and anode electrodes, said cathode, grid and anodeelectrodes each being provided with a, plurality of terminal leads, saidcircuit including a pair of concentric collar-like elements ofconducting material having equal lengths parallel to their axis, saidcollar-like elements being coextensive in a direction parallel to theiraxis, one of said collarlike members being connected to the grid leadsand the other collar-like element being connected to the anode leads forexciting said oscillator circult, and a hollow shielding conductingmember surrounding the concentric collar-like elements of conductingmaterial, and a tubular extension mounted on said shielding member, theinterior of which opens into the interior of said shielding member, saidcathode leads extending through said tubular extension and means in saidextension for tuning said cathode leads.

7. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and anode, the grid and anode of eachof said devices each being provided with a plurality of terminal leads,a pair of concentric collar-like elements between which and throughwhich said electron discharge devices extend, said electron dischargedevices being oppositely disposed and spaced around said collar-likeelements, the grid leads of said electron discharge devices beingconnected to one of said collar-like elements and the anode leads of theelectron discharge devices being connected to the other of saidcollar-like elements.

8. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and anode, the grid and anode of eachof said devices each being provided with a plurality of terminal leads,a pair of concentric collarlike elements between which and through whichsaid electron discharge devices extend and around which said electrondischarge devices are spaced, the grid leads of said electron dischargedevices being connected to one of said collar-like elements and theanode leads of the electron discharge devices being connected to theother of said collar-like elements, and a cathode lead for the cathodesof each of said electron discharge devices, and means for tuning saidcathode leads.

9. An oscillator including a pair of electron discharge devices, each ofwhich has a cathode, grid and anode, the grid, anode and cathode beingprovided with terminal leads, a pair of concentric collar-like elementsbetween which and through which said electron discharge devices extend,said electron discharge devices being oppositely disposed, the gridterminal leads of said electron discharge devices being connected to oneof said collar-like elements and the anode terminal leads of theelectron discharge devices being connected to the other of saidcollar-like elements, and shielding means surrounding said electrondischarge device and said collar-like elements, and means extending fromone side of said shielding means through which the cathode leads extend,and means within said extension for varying the effective length of saidcathode leads for tuning the same.

10. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and an anode, the grid, anode andcathode of each device being provided with terminal leads, a pair ofconcentric collar-like elements between which and through which saidelectron discharge devices extend, said electron discharge devices beingspaced around said concentric collar-like elements, the grid terminalleads of said electron discharge devices being connected to one of saidcollar-like elements, and the anode terminal leads of the electrondischarge devices being connected to the other of said collar-likeelements, and shielding means surrounding said electron dischargedevices and said collar-like elements.

11. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and an anode, the grid, anode andcathode of each device being provided with terminal leads, a pair ofconcentric collar-like elements around which said electron dischargedevices are positioned, the grid terminal leads of said electrondischarge devices being connected to one of said collar-like elements,and the anode terminal leads of the electron discharge devices beingconnected to the other of said collar-like elements, said collar-likeelements having a circumference equal to a multiple of half wavelengthsof the operating frequency, the terminal leads of said electrondischarge devices being connected at half wavelength intervals.

12. An oscillator including a pair of electron discharge devices, eachof which has a cathode, grid and anode, each grid and anode beingprovided with a plurality of terminal leads, a pair of collar-likeconducting members concentric with each other and provided withoppositely disposed apertures for receiving said electron dischargedevices and supporting the same Within said apertures, contacts on saidcollar-like conducting members adjacent said apertures for receivingsaid terminal leads, the terminal leads of said grids being connected tocontacts in one of said collar-like conducting members, and the terminalleads of the anodes being connected to the contacts of another of saidcollar-like conducting members.

13. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and anode, each grid and anode beingprovided with a plurality of terminal leads, a pair of collar-likeconducting elements concentric with each other, the terminal leads onsaid grids being connected to one of said collar-like elements, and theterminal leads on the anodes bein connected to another of saidcollar-like elements, a, shielding means surrounding said electrondischarge devices and said collar-like conducting elements, conductingmeans extending between but out of contact with said collar-likeelements and movable between said electron discharge devices, and meanssupported by said shielding means for supporting and moving saidconducting means between said electron dis- 8 charged devices forvarying the resonant frequency of said oscillator.

14. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and anode, said grids, anodes andcathodes being provided with terminal leads, a pair of collar-likeconducting members concentric with each other, the terminal leads onsaid grids being connected to one of said collar-like members and theterminal leads on said anodes being connected to another of saidcollar-like members, a shielding casing surrounding said electrondischarge devices and said collar-like conducting members, a firsttubular member extending from said shielding casing, a plurality ofsmaller tubular members within and coextensive with the first tubularmember, the cathodes of said electron discharge devices being of thefilament type and provided with a center tap lead, the center tap leadof said cathodes being connected to the smaller tubular members, theother terminal leads of said cathodes extending through said smallertubular members, and movable conducting means within said first tubularmember slidably supported on said smaller tubular members for tuning thecathode leads.

15. An oscillator including a plurality of electron discharge devices,each of which has a cathode, grid and anode, said grids, anodes andcathodes being provided with terminal leads, a pair of collar-likeconducting members concentric with each other, the terminal leads onsaid grids being connected to one of said collar-like members and theterminal leads on said anodes being connected r to the other of saidcollar-like members, a shielding casing surrounding said electrondischarge devices and said collar-like conducting members, a firsttubular member extending from said shielding casing, a plurality ofsmaller tubular members Within and coextensive with said first tubularmember, the cathodes of said electron discharge devices each beingprovided with three leads, one of which is electrically connected to oneof said smaller tubular members and the others of which extend throughthe smaller tubular member, and means for closing the end of the firsttubular member.

16. An oscillator circuit apparatus for use with a plurality of electrondischarge devices, each of which has a cathode, grid and anode, saidcircuit apparatus including a pair of collar-like conducting membersconcentric with each other, the anodes of said electron dischargedevices being connected to one of said collar-like conducting membersand the grids of said electron discharge devices being connected to theother of said collar-like conducting members, and a drum-like shieldingmember surrounding said collar-like conducting members, a tubular memberextending from one side of said drum-like Shielding member, the interiorof said tubular member communicating with the interior of the drum-likeshielding member, and a plurality of parallel elongated elementssupported within said tubular member and extending within the drum-likeshielding member, the cathodes of said electron discharge devices beingconnected to said parallel elongated members, oppositely disposedconducting means extending between but out of contact with saidcollar-like conducting members, means for rotatably supporting saidconducting means from one wall of said drum-like shielding member, andmeans for rotating said supporting means to vary the position of saidconducting means between said collar-like members.

17. An oscillator circuit apparatus for use with a plurality of electrondischarge devices, each of which has a cathode, grid and anode, saidcircuit apparatus including a pair of collar-like conducting membersconcentric with each other, the anodes of said electron dischargedevices being connected to one of said collar-like conduct members andthe grids of said electron discharge devices being connected to theother of said collar-like conducting members, and a drum lilee shieldingmember surrounding said collar-like conducting members, a tubular memberextending from one side of said drum-like shielding member, the interiorof said tubular member communicating with the interior of the drum-likeshielding member, a plurality of parallel elongated elements supportedWithin tubular member and extendin within the drum-like shieldingmember, the cathodes of said electron discharge devices being connectedto said par allel elongated members.

18. A combined oscillator and amplifier including a first group ofelectron discharge devices, each of which has a cathode, grid and ananode, the grids, anodes cathodes being provided with terminal leads, afirst pair of concentric collar-lilre members, the terminal leads ofsaid grids being connected to one of said colla -like bers and the anodeleads on said electron discharge device being connected to the other ofsaid collar-like members, hollow shielding means surrounding saidelectron discharge devices said collar-like members, cathode terminalleads extending externally of said hollow shielding and conducting meanssurrounding said cathode terminal leads and extending from said hollowshielding means, a second group of electron discharge devices each ofwhich has a cathode, grid and anode, said last grids, anodes andcathodes being provided with terminal leads, a second pair of concentriccollar-like members, the grid terminal leads of said second group ofelectron discharge devices being connected to one of said second pair ofcollar-like members and the anode terminal leads of said second group ofelectron discharge devices being connected to the other of said secondpair of concentric collar-like members and a hollow conducting membersurrounding said second group of electron discharge devices and saidsecond pair of collar-like elements, the cathode terminal leads of saidsecond group of electron discharge devices extending externally of saidhollow conducting member, and cnducting means surrounding the cathodeterminal leads of said second group of electron discharge devices, andextending from said hollow conducting memher, and means for coupling thecathode leads of the two groups of electron discharge devices.

19. A combined oscillator and amplifier including a plurality of groupsof electron discharge devices, each of which electron discharge deviceshas a cathode, grid and an anode, a plurality of pairs of concentriccollar-like members one of said groups of electron discharge deviceshaving its anodes connected to one of the collarlike members of one pairand its grids connected to the other of said collar-like members of saidone pair, and another group of said electron discharge devices havingits anodes connected to one of the collar-like members of another pairof concentric collar-like members and the grids connected to the otherof the collar-like members of said other pair, and a hollow conductingmeans surrounding said concentric collar-like members and theirassociated electron discharge devices a d having a partition forelectrically shielding of collar-like members and their associatedelectron discharge devices from each other.

A comb ned oscillator amplifier includ ing a plural .y of groups ofelectron discharge devices, each. vhic'n electron discharge devices hasa cathode, grid and an anode, plurality of pairs of concentriccollar-like members, one of said groups of electron discharge deviceshavin its anodes connected to one of he collar-like members of one pairand its :ids connected to the other of said collar-like members oi. thesame pair, and another of said groups of electron discharge deviceshaving the ano es connected to a collar-like member of another pair andthe grids connected to the other collar-like member of the lastmentioned pair of collar-lile members, hollow conducting meanssurrounding said pairs of concentric collar-like members and theirassociated electron discharge devices and a partition extending acrosssaid hollow conducting means for separately enclosing each of saidcollar-like members and their associated electron discharge devices andmeans for coupling one pair of concentric collar-like members and theirassociated electron discharge devices with another pair of collar-likemembers and their associated electron discharge devices.

21. A combined amplifier and oscillator comprising a hollow drum-likeconducting member and conducting means dividing said drum-likeconducting member into two compartments, a pair of concentriccollar-like members within one or said compartments, and electrondischarge devices, each of which has a cathode, grid and anode, thegrids being connected to one of said collar-like members and the anodesbeing connected to the other of said collar-like members, and a secondpair of concentric collar-like members in the other compartment, andelectron discharge devices, each of which has a cathode, grid and anode,the anodes being connected to one of REFERENCES CITED The followingreferences are of record in the file of this patent:

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